As Faith attempts to seduce Angel and steal his soul, the Mayor summons a dark-magic demon to finish the job.
Horned Demon Skyler offers the slayers to sell them the Books of Ascension for $5,000, so he can flee from the Hell-mouth by plane; Faith informs the Mayor, who makes her steal them and kill Skyler, then turn to Angel 'scared' to seduce him but fails. Buffy consults the gang plus Wesley, they find a reference to a 1723 precedent when a whole English village disappeared. The mayor enlists someone in a ninja suit who manages to turn Angel back into Angelus by stealing his soul with Faith's help, they become lovers. The mayor demonstrates his invulnerability and approves Angelus's plan to capture and torture Buffy, just not kill her soon to avoid a replacement, again Faith helps, but actually...
- Buffy and Angel went to see a movie, but it was very steamy and both are worked up. To prove that he isn't going to lose control, Angel kisses her, but their sweet moment is cut short when Faith shows up for patrol. While out hunting for the bad guys, the two slayers run into a demon (named Skyler in the script, though his name is not spoken) who offers them a set of books about ascension in exchange for five grand. Apparently, these books would be very useful for the Mayor and when he finds out, he asks Faith to kill the demon and take the books.
At the library, the Scooby Gang discusses "ascension" but they know very little about it until Willow suggests checking in a book which Giles was trying to hide from her due to its magical content. Cordelia arrives and makes a date with Wesley. Faith finds the demon, who's desperate to get out of Sunnydale before the Mayor's ascension, and kills him. She goes to Angel, upset over what she's become and seeks comfort from him. Angel refuses to give her what she wants, but Faith manages to sneak a kiss on the cheek which Buffy happens to walk in and see.
Faith then reports to the Mayor about her failure. She was trying to take away his soul with happiness but since Angel's mind is focused on Buffy. The Mayor decides that he'll have to take it in the "most painful way imaginable".
Buffy reports in to Giles and Wesley, but having just seen Faith with Angel, a little upset and reluctant to do anything with Faith. After Xander gets the address for the demon from Willy, Buffy goes to find him, and Faith arrives just in time to tag along. When the two reach the demon's apartment, they find him dead and Buffy is worried by Faith's strange behavior about it.
At his office, the Mayor talks to a cloaked man, a sorcerer of some sort, about taking Angel's soul away from him.
Meanwhile, Buffy tells Willow about how she saw Faith and Angel together, and Willow encourages, rather forces Buffy to talk to Angel about it.
Faith finds Angel first at the mansion and apologizes for her behavior the night before, and then she pours blood onto his shirt. The cloaked man steps out of the shadows, chants a spell, lights flash, Angel yells, and then Angelus is back. He pulls Faith to him and they kiss before Angel starts beating her up. The two fight and Faith ends up on top, holding a stake to his heart. A truce is made as Angel agrees to meet the Mayor and the two kiss.
The Scooby gang meets again, and makes plans for the night. Willow reveals that she was unable to find anything in the Mayor's computer files since the files were emptied before she could get through to them. Unable to find both Faith and Angel, Buffy leaves to find out what's going on with the Mayor while Wesley takes a very eager Cordelia and the rest of the group, minus Xander, to the Hall of Records to find information on the Mayor.
Faith takes Angel to meet with the Mayor, and Angel tries to kill him, but discovers that the Mayor can't be killed. He tells the Mayor of his plans to torture and kill Buffy. The two walk the streets of Sunnydale on the way to Buffy's house, and encounter Xander who Angel punches and knocks to the ground. After flirting mildly with Joyce, Angel and Faith find Buffy in her room and lure her away to the mansion hinting slightly at their changed behavior making Buffy worried as she follows them. Once there, Angel and Faith reveal that they're fighting for the other side now, and Angel knocks Buffy out cold.
Angel chains Buffy to a wall, where she wakes up finding Angel and Faith planning to torture her. Faith goes on about her painful childhood with a mother who drank too much, and her life as the Slayer living in Buffy's shadow. She reveals what she knows about the Mayor's master plans, which will culminate with the ascension taking place on Graduation Day. Finally, Faith says with a smile, boasting her ability to deceive the Scoobies: "What can I say? I'm the world's best actor." Angel responds: "Second best." Faith then realizes that SHE was the one who was duped -- Angel was only pretending to be Angelus again, when in reality he still retained his soul, and Buffy slips out of her chains. The two of them had been pretending so that they could find out as much about the ascension as possible. The rest of the Scooby gang arrive as Buffy and Faith fight and end up with knives at each other's throats. Telling Buffy that she can't kill her without becoming her, Faith breaks away and runs off.
At the library, Giles thanks and bids good-bye to the cloaked man, revealing that the fake spell was the paying off of a debt the man owed Giles for introducing him to his wife. Wesley is very upset that Giles did all this behind his back, and plans to tell the council about it. Now that everyone is fully aware of Faith's switch to Team Evil, they have to prepare to fight her as well. Faith is upset over the whole ordeal, but the Mayor tells her not to worry because after the ascension, they'd all be dead.
Buffy goes to Angel, and both are having a hard time dealing with what they had to do. Angel feels horrible that he had to do and say the things he did, and how far he let it go. Buffy needs some time, but as she leaves, he asks, "You still my girl?" and she responds, "Always."